Recent progress on batch processed large size LRE-123 bulk superconductors using a novel thin film Nd-123 seed

We developed a batch production of large grain c-axis oriented GdBa ₂Cu₃O_y and SmBa₂Cu₃O _y bulk superconductors by using a cold seeding method in air. Novel thin film Nd-123 seeds grown on MgO crystals were used as a seed crystal for the batch process. Four pieces of single domain Gd-123 samples with 50 mm in diameter were successfully fabricated in single run. Magnetization results confirmed that the samples have a sharp superconducting transition with the onset T_c around 93 K. On the other hand Sm-123 system was studied as a function of varying amounts of BaO₂ to reduce the Sm/Ba solid state substation and batch production in air. The magnetization results indicated that superconducting transition was increased with increasing the BaO ₂ concentration from 91.5 K for 0 wt% to 93 K for 0.2 and 0.3 wt%. Moreover, the maximum trapped field of 2.1 T and 1.5 T at 20 K was recorded 16 mm in diameter Sm-123 with 3 and 1 wt% BaO₂ addition.